Books have been stated on this topic, and the debates and discourse about where the "hot" slot games are located in a casino are still happening – more than 60 years after slot machines were first installed in gambling houses.
The standard rule is that the most favorable slot machines were installed just inside the entry of the casino; so that folks walking by would be able to see actual jackpot winners and be captivated to come inside … play. Our speculation is that this is definitely no longer true.
The great majority of the mega casinos these days are mammoth complexes … it’s no longer possible to see inside from the sidewalk, so there is no longer a reason to place the ‘loose’ one armed bandits in close proximity to any doorways.
An additional traditional rule is that loose slot machine games are put on the major aisles inside the casinos, again so that more fun seekers could see winning jackpots and be inspired to play. Importantly however, we find that this also isn’t a universal rule any more.
What casinos found over the years is that people walking down the busy aisles were frequently on the way to somewhere else. If they played slot machine games at all, they would simply put in their loose change because they happened to be walking by. Win or lose, they would very often not stop to keep playing. And the very last thing a casino wants is for someone to win a jackpot by playing only a few coins and then not stay to put it all back in!
These days, casinos are constantly changing their perspective about where to place the loose slot machines.